#CalStatistic.py
import numbers
from stat import ST_DEV


def getNum():
    nums = []
    iNumStr = input("请输入数字(回车退出):")
    while iNumStr!="":
        nums.append(eval(iNumStr))
        iNumStr = input("请输入数字(回车退出):")
    return nums
        
def mean(numbers):
    s = 0.0
    for num in numbers:
        s += num
    return s / len(numbers)

def dev(numbers,mean):
    sdev = 0.0
    for num in numbers:
        sdev += (num - mean) ** 2
    return pow(sdev/len(numbers),0.5)

def median(numbers):
    sorted(numbers)
    size = len(numbers)
    if size % 2 == 0:
        med = (numbers[size//2-1] + numbers[size//2])/2
    else:
        med = numbers[size//2]
    return med

n = getNum()
m = mean(n)
print("平均值:{},方差:{:.2},中位数:{}".format(m,dev(n,m),median(n)))

